Microarray analysis of Akt1 activation in transgenic mouse hearts reveals transcript expression profiles associated with compensatory hypertrophy and failure

2006 ◽  
Vol 27 (2) ◽  
pp. 156-170 ◽  
Author(s):  
Stephan Schiekofer ◽  
Ichiro Shiojima ◽  
Kaori Sato ◽  
Gennaro Galasso ◽  
Yuichi Oshima ◽  
...  

To investigate molecular mechanisms involved in the development of cardiac hypertrophy and heart failure, we developed a tetracycline-regulated transgenic system to conditionally switch a constitutively active form of the Akt1 protein kinase on or off in the adult heart. Short-term activation (2 wk) of Akt1 resulted in completely reversible hypertrophy with maintained contractility. In contrast, chronic Akt1 activation (6 wk) induced extensive cardiac hypertrophy, severe contractile dysfunction, and massive interstitial fibrosis. The focus of this study was to create a transcript expression profile of the heart as it undergoes reversible Akt1-mediated hypertrophy and during the transition from compensated hypertrophy to heart failure. Heart tissue was analyzed before transgene induction, 2 wk after transgene induction, 2 wk of transgene induction followed by 2 days of repression, 6 wk after transgene induction, and 6 wk of transgene induction followed by 2 wk of repression. Acute overexpression of Akt1 (2 wk) leads to changes in the expression of 826 transcripts relative to noninduced hearts, whereas chronic induction (6 wk) led to changes in the expression of 1,611, of which 65% represented transcripts that were regulated during the pathological phase of heart growth. Another set of genes identified was uniquely regulated during heart regression but not growth, indicating that nonoverlapping transcription programs participate in the processes of cardiac hypertrophy and atrophy. These data define the gene regulatory programs downstream of Akt that control heart size and contribute to the transition from compensatory hypertrophy to heart failure.

Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
Shuichi Yoneda ◽  
Saptarsi M Haldar ◽  
Jessica Jenkins ◽  
Yunmei Wang ◽  
Teruo Inoue ◽  
...  

Introduction: Pathologic cardiac hypertrophy is a maladaptive response to neurohormonal and hemodynamic stress that is a hallmark of human heart failure. While inflammation has been implicated in pathologic hypertrophy, the molecular mechanisms underlying innate immune dysregulation in this disease process are incompletely defined. We have previously demonstrated that the forkhead transcription factor Foxp1 controls monocyte differentiation and suppresses inflammatory activation of macrophages. In this study, we hypothesized that monocyte/macrophage Foxp1 regulates pathologic cardiac hypertrophy. Methods: Macrophage-specific Foxp1 over-expressing (macFoxp1tg=anti-inflammatory) vs. non-tg controls, as well as macrophage-specific Foxp1 knockdown (macFoxp1ko=pro-inflammatory) vs. Cre-control male mice were subject to chronic angiotensin II (AII) infusion (1.8 mcg/kg/min via subcutaneous osmotic mini-pump) for 4 weeks. Results: AII-mediated cardiac hypertrophy (heart mass and cardiomyocyte cross-sectional area), left ventricular (LV) systolic dysfunction, LV dilation, interstitial fibrosis and macrophage (Mac-3+ cells) accumulation were significantly attenuated in macFoxp1tg mice compared to non-tg controls. In contrast, AII-mediated cardiac hypertrophy, LV systolic dysfunction and cavity dilation were significantly exacerbated in macFoxp1ko mice compared to Cre controls. There were no differences in systemic blood pressure between these groups, corroborating a load-independent role for macrophage Foxp1 in cardiac hypertrophy. Conclusion: These studies identify macrophage Foxp1 as a novel negative regulator of pathologic cardiac hypertrophy in vivo. Modulation of Foxp1 signaling may provide a novel strategy for prevention and treatment of heart failure.


Circulation ◽  
2008 ◽  
Vol 118 (suppl_18) ◽  
Author(s):  
Biswajit Das ◽  
David Young ◽  
Amit Vasanji ◽  
Sudhiranjan Gupta ◽  
Zoran Popovic ◽  
...  

Myotrophin (Myo), a 12-kDa protein, stimulates myocyte growth and is a factor in initiating cardiac hypertrophy (CH). Cardiospecific overexpression of Myo in transgenic mice (Myo-Tg) induces hypertrophy that progresses to heart failure (HF). Oligonucleotide gene array revealed upregulation of a p53 homologue gene (EST- AI843106 ) in Myo-Tg mice during HF, indicating that p53 plays an important role during the transition of hypertrophy to HF. To dissect out the mechanisms of p53-mediated Myo-induced CH/HF, we developed a double-transgenic mouse line (p53 −/− /myo +/+ ) by crossing Myo-Tg mice with p53-null mice. The double transgenic mice showed a significant attenuation of cardiac mass compared to Myo-Tg mice (heart weight:body weight ratio; 5.2 ± 0.21 vs. 7.9 ± 0.58, p < 0.001) associated with improved cardiac function and downregulation of ANF expression, suggesting that hypertrophy induced by Myo overexpression is indeed mediated through p53. To elucidate the relationship between p53 and Myo-induced hypertrophy, we performed a Reverse-Transcription Real-Time PCR pathway array on heart tissues from p53 −/− /myo +/+ vs. Myo-Tg mice. A bioinformatic approach, Ingenuity Pathway Analysis TM (IPA), was used to analyze the selected up-/downregulated genes. The IPA network showed that among the up-/downregulated genes, Bcl2, Brca1, Cdkn1a and Myc occupy the nodal position, whereas E2f1 , Pmaip1 , Gadd45a and Pttg1 function as peripheral candidates. The expression profiles of some genes of the p53 pathway were validated by immunoblot analysis. Functional assignment of these selected candidate genes showed that Bcl2, E2f1 and FasL are related to CH/HF, but the function of Gadd45a, Pmaip1, and Vcan is still unknown. Apart from these p53 cascade members, we also found that other molecules (e.g., Jnk, Ras, NF-kB, Cyclin L, and Mek) may be involved in an intricate interplay to stimulate p53-mediated Myo-induced CH. Suppression of NF-kB activity (by electrophoresis mobility shift assay) in p53 −/− /myo +/+ mice compared to Myo-Tg mice indicated involvement of NF-kB, as predicted by IPA, in Myo/p53 cross-talk. Our data suggest that the p53 signaling cascade actively participates in progression of hypertrophy to HF, triggered by overexpression of myotrophin.


2013 ◽  
Vol 113 (suppl_1) ◽  
Author(s):  
Sanjeewa A Goonasekera ◽  
Jop van Berlo ◽  
Adam R Burr ◽  
Robert N Correll ◽  
Allen J York ◽  
...  

Background: STIM1, an ER/SR resident Ca 2+ sensing protein regulates Ca 2+ entry following internal Ca 2+ store depletion in a broad range of tissues and cell types. However their putative roles in excitable tissue such as cardiac myocytes is uncertain. Results: Here we generated a mouse model of STIM1 overexpression in cardiac and skeletal muscle. Western blot analysis suggested approximately 4-6 fold STIM1 overexpression in Tg mouse hearts compared to Ntg littermates. Immunocytochemistry carried out in ventricular myocytes revealed that STIM1 and the cardiac ryanodine receptor (RyR2) co-localize. Functionally, the amplitude of Ca 2+ entry following SR Ca 2+ depletion was 2-fold greater in myocytes isolated from STIM1 Tg mice compared to NTg littermates. Echocardiographic analysis in STIM1 Tg mice showed age dependent remodeling of the myocardium with a significant decrease in fractional shortening at 16 weeks of age (14.4.5±3.8 in STIM1 Tg vs. 36.9±1.5 in Ntg). These changes were accompanied by a significant increase in heart weight to tibia length (13.6 +/- 1.4 vs 6.5 +/- 0.24) and increased lung weight to tibia length ratio (11.6+/- 2.1 vs 8.1 +/- 0.38) in STIM1 Tg mice compared to Ntg littermates. Photometry experiments in isolated ventricular myocytes demonstrated significantly increased Ca 2+ transient amplitude with an unexpected decrease in the SR Ca 2+ load associated with STIM1 overexpression. In addition transgenic mice showed increased calcineurin-nuclear factor of activated T cells (NFAT) activation in vivo, increased CaMKII activity, interstitial fibrosis and exaggerated hypertrophy following two weeks of neuroendocrine agonist or pressure overload stimulation. Conclusion: Our observations suggest that STIM1 overexpression by itself can lead to cardiac hypertrophy and contribute to pathological cardiac remodeling and possibly sudden cardiac death. The molecular mechanisms underlying these phenomena are currently under investigation.


Author(s):  
Hideaki Inazumi ◽  
Koichiro Kuwahara ◽  
Yasuaki Nakagawa ◽  
Yoshihiro Kuwabara ◽  
Takuro Numaga-Tomita ◽  
...  

Background: During the development of heart failure, a fetal cardiac gene program is reactivated and accelerates pathological cardiac remodeling. We previously reported that a transcriptional repressor, neuron restrictive silencer factor (NRSF), suppresses the fetal cardiac gene program, thereby maintaining cardiac integrity. The underlying molecular mechanisms remains to be determined, however. Methods: We aim to elucidate molecular mechanisms by which NRSF maintains normal cardiac function. We generated cardiac-specific NRSF knockout mice and analyzed cardiac gene expression profiles in those mice and mice cardiac-specifically expressing a dominant-negative NRSF mutant. Results: We found that cardiac expression of Gαo, an inhibitory G protein encoded in humans by GNAO1, is transcriptionally regulated by NRSF and is increased in the ventricles of several mouse models of heart failure. Genetic knockdown of Gnao1 ameliorated the cardiac dysfunction and prolonged survival rates in these mouse heart failure models. Conversely, cardiac-specific overexpression of GNAO1 in mice was sufficient to induce cardiac dysfunction. Mechanistically, we observed that increasing Gαo expression increased surface sarcolemmal L-type Ca 2+ channel activity, activated Calcium/calmodulin-dependent kinase-II (CaMKII) signaling and impaired Ca 2+ handling in ventricular myocytes, which led to cardiac dysfunction. Conclusions: These findings shed light on a novel function of Gαo in the regulation of cardiac Ca 2+ homeostasis and systolic function and suggest Gαo may be an effective therapeutic target for the treatment of heart failure.


2010 ◽  
Vol 298 (6) ◽  
pp. H2082-H2092 ◽  
Author(s):  
Yonggang Liu ◽  
Man Yu ◽  
Ling Wu ◽  
Michael T. Chin

Cardiac hypertrophy is a common response to hemodynamic stress in the heart and can progress to heart failure. To investigate whether the transcription factor cardiovascular basic helix-loop-helix factor 1/hairy/enhancer of split related with YRPW motif 2 (CHF1/Hey2) influences the development of cardiac hypertrophy and progression to heart failure under conditions of pressure overload, we performed aortic constriction on 12-wk-old male wild-type (WT) and heterozygous (HET) mice globally underexpressing CHF1/Hey2. After aortic banding, WT and HET mice showed increased cardiac hypertrophy as measured by gravimetric analysis, as expected. CHF1/Hey2 HET mice, however, demonstrated a greater increase in the ventricular weight-to-body weight ratio compared with WT mice ( P < 0.05). Echocardiographic measurements showed a significantly decreased ejection fraction compared with WT mice ( P < 0.05). Histological examination of Masson trichrome-stained heart tissue demonstrated extensive fibrosis in HET mice compared with WT mice. TUNEL staining demonstrated increased apoptosis in HET hearts ( P < 0.05). Exposure of cultured neonatal myocytes from WT and HET mice to H2O2 and tunicamycin, known inducers of apoptosis that work through different mechanisms, demonstrated significantly increased apoptosis in HET cells compared with WT cells ( P < 0.05). Expression of Bid, a downstream activator of the mitochondrial death pathway, was expressed in HET hearts at increased levels after aortic banding. Expression of GATA4, a transcriptional activator of cardiac hypertrophy, was also increased in HET hearts, as was phosphorylation of GATA4 at Ser105. Our findings demonstrate that CHF1/Hey2 expression levels influence hypertrophy and the progression to heart failure in response to pressure overload through modulation of apoptosis and GATA4 activity.


2019 ◽  
Vol 39 (12) ◽  
Author(s):  
Mengfei Cao ◽  
Wei Yuan ◽  
Meiling Peng ◽  
Ziqi Mao ◽  
Qianru Zhao ◽  
...  

Abstract Pathological cardiac hypertrophy is a complex process and eventually develops into heart failure, in which the heart responds to various intrinsic or external stress, involving increased interstitial fibrosis, cell death and cardiac dysfunction. Studies have shown that oxidative stress is an important mechanism for this maladaptation. Cyclophilin A (CyPA) is a member of the cyclophilin (CyPs) family. Many cells secrete CyPA to the outside of the cells in response to oxidative stress. CyPA from blood vessels and the heart itself participate in a variety of signaling pathways to regulate the production of reactive oxygen species (ROS) and mediate inflammation, promote cardiomyocyte hypertrophy and proliferation of cardiac fibroblasts, stimulate endothelial injury and vascular smooth muscle hyperplasia, and promote the dissolution of extracellular matrix (ECM) by activating matrix metalloproteinases (MMPs). The events triggered by CyPA cause a decline of diastolic and systolic function and finally lead to the occurrence of heart failure. This article aims to introduce the role and mechanism of CyPA in cardiac hypertrophy and remodeling, and highlights its potential role as a disease biomarker and therapeutic target.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Ning Zhou ◽  
Xin Chen ◽  
Jing Xi ◽  
Ben Ma ◽  
Christiana Leimena ◽  
...  

Abstract Pressure overload-induced cardiac hypertrophy, such as that caused by hypertension, is a key risk factor for heart failure. However, the underlying molecular mechanisms remain largely unknown. We previously reported that the valosin-containing protein (VCP), an ATPase-associated protein newly identified in the heart, acts as a significant mediator of cardiac protection against pressure overload-induced pathological cardiac hypertrophy. Still, the underlying molecular basis for the protection is unclear. This study used a cardiac-specific VCP transgenic mouse model to understand the transcriptomic alterations induced by VCP under the cardiac stress caused by pressure overload. Using RNA sequencing and comprehensive bioinformatic analysis, we found that overexpression of the VCP in the heart was able to normalize the pressure overload-stimulated hypertrophic signals by activating G protein-coupled receptors, particularly, the olfactory receptor family, and inhibiting the transcription factor controlling cell proliferation and differentiation. Moreover, VCP overexpression restored pro-survival signaling through regulating alternative splicing alterations of mitochondrial genes. Together, our study revealed a novel molecular regulation mediated by VCP under pressure overload that may bring new insight into the mechanisms involved in protecting against hypertensive heart failure.


Circulation ◽  
2020 ◽  
Vol 142 (Suppl_3) ◽  
Author(s):  
Kisuk Min ◽  
Yan Huang ◽  
Frank J Giordano ◽  
Sudip Bajpeyi ◽  
Anton M Bennett

Introduction: Cardiac remodeling occurs in response to pathological stimuli including chronic pressure overload, subsequently leading to heart failure. Despite considerable research efforts, the molecular mechanisms responsible for heart failure have yet to be fully elucidated. One of the prominent signaling pathways involved in the development of pathological cardiac hypertrophy is the mitogen-activated protein kinases (MAPKs) pathways. The MAPKs are inactivated by the MAPK phosphatases (MKPs) through direct dephosphorylation. Growing evidence suggests the importance of MKP-5 signaling mechanisms in physiological and pathological processes. However, the role of MKP-5 has not been explored in cardiac muscle. The objective of this study is to investigate how MKP-5-mediated MAPK activity contributes to mechanisms responsible for pressure overload-induced cardiac hypertrophy. Hypothesis: We tested the hypothesis that MKP-5 serves as a central regulator of MAPKs in pressure overload-induced cardiac hypertrophy. Methods: To investigate the role of MKP-5 in cardiac muscle, we caused pressure overload-induced cardiac hypertrophy in wild type (mkp-5 +/+ ) mice and MKP-5 deficient mice (mkp-5 -/- ) through transverse aortic constriction (TAC). Cardiac function was evaluated by echocardiographic analysis at 4 weeks after TAC. Cardiac hypertrophy was measured by heart-to-body weight ratio. Interstitial myocardial fibrosis was evaluated by Sirius red stains and expression of fibrogenic genes was determined by quantitative PCR. Results: Echocardiographic analysis showed that the ejection fraction and fractional shortening of mkp-5 +/+ mice significantly decreased by at 4 weeks after TAC. Heart-to-body weight ratio increased in mkp-5 +/+ mice. However, MKP-5-deficient heart was protected from cardiac dysfunction and cardiac hypertrophy induced by TAC. Importantly, the fibrogenic genes were markedly reduced in mkp-5 -/- mice as compared with mkp-5 +/+ mice at 4 weeks after TAC. Conclusions: Collectively, our study demonstrates that MKP-5 deficiency prevents the heart from pressure overload-induced cardiac hypertrophy and suggests that MKP-5 may serve as a novel therapeutic target for treatment of heart disease.


2005 ◽  
Vol 21 (1) ◽  
pp. 34-42 ◽  
Author(s):  
Sek Won Kong ◽  
Natalya Bodyak ◽  
Patrick Yue ◽  
Zhilin Liu ◽  
Jeffrey Brown ◽  
...  

Cardiac hypertrophy is a complex and nonhomogenous response to various stimuli. In this study, we used high-density oligonucleotide microarray to examine gene expression profiles during physiological hypertrophy, pathological hypertrophy, and heart failure in Dahl salt-sensitive rats. There were changes in 404/3,160 and 874/3,160 genes between physiological and pathological hypertrophy and the transition from hypertrophy to heart failure, respectively. There were increases in stress response genes (e.g., heat shock proteins) and inflammation-related genes (e.g., pancreatitis-associated protein and arachidonate 12-lipoxygenase) in pathological processes but not in physiological hypertrophy. Furthermore, atrial natriuretic factor and brain natriuretic protein showed distinctive changes that are very specific to different conditions. In addition, we used a resampling-based gene score-calculating method to define significantly altered gene clusters, based on Gene Ontology classification. It revealed significant alterations in genes involved in the apoptosis pathway during pathological hypertrophy, suggesting that the apoptosis pathway may play a role during the transition to heart failure. In addition, there were significant changes in glucose/insulin signaling, protein biosynthesis, and epidermal growth factor signaling during physiological hypertrophy but not during pathological hypertrophy.


2021 ◽  
Author(s):  
Matteo D'Antonio ◽  
Jennifer P. Nguyen ◽  
Timothy D. Arthur ◽  
Hiroko Matsui ◽  
Margaret K.R. Donovan ◽  
...  

Transcriptome-wide expression changes occur during heart failure, including reactivation of fetal-specific isoforms. However, the underlying molecular mechanisms and the extent to which a fetal gene program switch occurs remains unclear. Limitations hindering transcriptome-wide analyses of alternative splicing differences (i.e. isoform switching) in cardiovascular system (CVS) tissues between fetal and adult (healthy and diseased) stages have included both cellular heterogeneity across bulk RNA-seq samples and limited availability of fetal tissue for research. To overcome these limitations, we have deconvoluted the cellular compositions of 996 RNA-seq samples representing heart failure, healthy adult (heart and arteria), and fetal-like (iPSC-derived cardiovascular progenitor cells) CVS tissues. Comparison of the expression profiles revealed that RNA-binding proteins (RBPs) are highly overexpressed in fetal-like compared with healthy adult and are reactivated in heart failure, which results in expression of thousands fetal-specific isoforms. Of note, isoforms for 20 different RBPs were among those that reverted in heart failure to the fetal-like expression pattern. We determined that, compared with adult-specific isoforms, fetal-specific isoforms are more likely to bind RBPs, have canonical sequences at their splice sites and encode proteins with more functions. Our findings suggest targeting RBP fetal-specific isoforms could result in novel therapeutics for heart failure.


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